2 Distillation Simple laboratory distillation Industrial distillation Fermentation and distillation
3 DistillationHow would you separate the yellow liquid from the green mixture?
4 Distillation Yellow bp = 100oC Blue bp = 80oC Green bp = 100oC How do we get to Blue liquid out of the Green mixture?
5 DistillationDistillation can separate one liquid from another in a mixture solutionDistillation works by evaporating one of the liquids from the solutionIt is then cooled and condensed into a separate containerThe other liquid is left behind
7 DistillationDistillation is used to purify a compound by separating it from a non-volatile or less-volatile materialWhen different compounds in a mixture have different boiling points they can be separated into individual components by distillation
8 Distillation Where is distillation used? Distillation is used to separate crude oil into specific fractions, such as petrol or keroseneWater is distilled to remove impurities (e.g. salt from seawater)Air is distilled to separate it into O2 and N2Distillation of fermented solutions has been used since ancient times to produce beverages with a high alcohol content
9 DistillationDistillation is a method of separating mixtures based on differences in their boiling pointsDistillation is a physical separation process and not a chemical reaction
12 DistillationBoiling points are measured by recording the temperature (within a specific range) on a thermometer while performing a distillationThe distillation method of boiling point determination measures the temperature of the vapours above the liquidThese vapours are in equilibrium with the boiling liquid and are the same temperature as the boiling liquid
13 DistillationThe boiling point: temperature at which the vapour pressure of the liquid phase of a solution equals the external (atmospheric) pressure acting on the surface of the liquidThe vapour pressure: is an indication of a liquid's evaporation rate. It relates to the tendency of particles to escape from the liquidA substance with a high vapour pressure at normal temperatures is referred to as volatile
14 DistillationThe vapour pressure of the liquid will increase as the temperature of the liquid increasesThese vapours are in equilibrium with the boiling liquid and are the same temperature as the boiling liquidWhen the vapour pressure equals the atmospheric pressure the liquid will boil
15 DistillationDifferent compounds boil at different temperatures because each has a different, characteristic, vapour pressureCompounds with higher vapour pressures will boil at lower temperatures (i.e. first to distil)
21 Distillation Industrial towers use reflux to separate products Reflux: down flowing liquid provides cooling and condensation of the up flowing vapoursFractions collected at specific parts of the towerThe more reflux that is provided the better the tower's separation of lower boiling materials from higher boiling materials
22 Fraction: a group of compounds with boiling points & carbon chains within a given range
23 DistillationFractionating columns use trays to help separate the mixture by allowing the mixed vapors to cool, condense, and vaporize againWith each condensation-vaporization cycle the vapors are enriched in a certain componentA larger surface area allows more cycles, improving separation.
24 DistillationWhen the process feed has a diverse composition (e.g. crude oil) outlets at intervals up the column allow for the withdrawal of different fractions collected on trays having different carbon chain lengths and boiling ranges
25 Distillation The lightest products (lowest boiling point) exit from the top of the columnThe heaviest products(highest boiling point)exit from the bottom of the column
27 DistillationEthanol fermentation is a biological process in which sugars such as glucose, fructose, or sucrose are converted into cellular energyThe metabolic waste produce are ethanol and carbon dioxideYeasts perform this conversion in the absence of oxygen: ethanol fermentation is anaerobicEthanol fermentation occurs in the production of alcoholic drinks, biofuel, and bread
28 DistillationA distilled beverage, liquor, or spirit is an alcoholic beverage containing ethanol (CH3CH2OH)Produced by distilling (i.e. concentrating by distillation) ethanol produced by means of fermenting grain, fruit, or vegetables
29 DistillationA still is a apparatus used to distill miscible or immiscible liquid mixtures by heating to selectively boil and then cooling to condense the vaporStills are used to produce beverages containing ethanol (CH3CH2OH)
31 Distillation Conclusion Distillation is a process of physically separating mixturesDifference in vapour pressure and boiling pointUsed in the laboratory, industry, and in the fermentation process
32 QuestionsWhat are the similarities and differences between the 3 methods of distillation?Why is temperature range related to purity?Would a mixture distil quicker or slower in a vacuum?4. Design an experiment to separate 3 liquids from a mixture